165972871 has 4 divisors (see below), whose sum is σ = 167279872. Its totient is φ = 164665872.

The previous prime is 165972857. The next prime is 165972881. The reversal of 165972871 is 178279561.

It is a happy number.

165972871 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 178279561 = 17 ⋅10487033.

It is a cyclic number.

It is not a de Polignac number, because 165972871 - 2⁷ = 165972743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165972881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 653310 + ... + 653563.

It is an arithmetic number, because the mean of its divisors is an integer number (41819968).

Almost surely, 2^165972871 is an apocalyptic number.

165972871 is a deficient number, since it is larger than the sum of its proper divisors (1307001).

165972871 is a wasteful number, since it uses less digits than its factorization.

165972871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1307000.

The product of its digits is 211680, while the sum is 46.

The square root of 165972871 is about 12883.0458743265. The cubic root of 165972871 is about 549.5565251590.

The spelling of 165972871 in words is "one hundred sixty-five million, nine hundred seventy-two thousand, eight hundred seventy-one".